Condenser for refrigerating apparatus



July 30, 1929. GREENWALD 1,722,699

CONDENSER FQR REFRIGERATING APPARATUS Filed March 21, 1927 Sum/14 50 0flQraZcZfl, Freeware 2 a lpatented July 11929. v v STATES can a. enema,

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0F DETRQIT, MICHIGAN, ASSIGN'OR T0 THOMAS C. WHITE- HEAID, 01E DE'IRQIT,MICHIGAN. i

1 nane connnnsnn nor. nnrnrennarmearrann'rns r Application flldd March21, 1927. Serial No. 177,093.

refrigeration it is usual to design the apparatus" so that thedesiredlow temperature may be maintained... in the refrigeratorcompartment by an intermittent circulation of therefrigerant controlledand regulated by a suitable thermostat. ][t is'also the usual practiceto efiect'the condensation of the compressed refrigerantnby circulatinga1r at room temperature through condensing coils by means of a fan orequivalent device. The object of my invention is to increase thecondenser efficiency by supplementing the air cooling means withadditional cooling means so incorporated in the apparatus as to bepractical in a domestic typeinstallation. E

For this purpose I have designed a condensing apparatus in which partor' all of the conduits for the'refrigerant arearranged in thermalcontact with certain chemical substances having hydroscopic ordeliquescent properties, or, in other words, having the property ofabsorbing moisture from the at mosphere. One substance particularlysuitable is calcium chloride. When this sub: stanceis arranged inthermal contact with the condenser coils and the refrigerating apparatusis in the portion of its intermittent cycle where the refrigerant is notcirculating, the calcium chlorideconti'nuously absorbs moisture from theatmosphere. When the circula- "tion through the condenser againcommences, the heat from the compressed refrigerant causes the absorbedmoisture in the calcium chloride to be reevaporated and this evaporaftion results in a cooling effect which assists in ,the; condensationofthe refrigerant. Thus if the condenser is sub'ected to air cooling inthe usual manner and also arranged in thermal contact. with ahygroscopic or deliquescent substance, the condensation of the refrigerant is accomplished by the combined cooling efiects of thecirculating air and the evaporation of the absorbed moisture. The factthat the refrigeratin system is intermittently operatedpermits t eproper. functioning of the calcium chloride as an additional coolingagent whenever its cooling efiect is required. It acts as a carrier forthe moisture which is alternately" absorbed and reevaporated. Theabsorption of the moisture is acnot absorbed to any material degree bythe recompanied by a heating effect, but as this 00- curs during theperiod when the refrigerant is not circulating, the heat acquired by thecondenser is" dissipated by radiation and is frigerant itself. On theother hard, when the refrigerant is in circulation the temperature ismaterially lowered by the cooling sheet 3 and the refrigerantloses partof its heat to the evaporated moisture. l

My invention is not limited in. application, to any particular type ofrefrigerating apparatus, but in order to more clearly illustrate apractical embodiment of the invention reference is made to theaccompanying drawings, wherein r 1 Figure 1 represents a refrigeratingsystem of the compression type to which my inven- I tion may be applied;

Figure 2 is a cross section through a con- 7 denser embodying myinvention; I

Figure 3 is a mo ified arrangement, for ob-, taining an additionalcooling edect in a re-; frigerant condenser.

Referring now to the drawings, 1 represents an electric motor, 2 asuitable compressor connected thereto by a shaft 3 on which is mounted afan 4. 5 is a condensing coil connected by a conduit 6 with the outletof the compressor and having at its base a reservoir 7 for the condensedrefrigerant. The, A condenser 5 is cooled by a circulation of airpromoted by the fan i and to aidin thecooling there is preferablyprovided a hood 8 surrounding the condenser, compressor and fan. 9represents diagrammatically a re- 'frigerator compartmeiit in which islocated 'sion valve 13 and compressor valve'll may be a'rrangedin .theusual-maer. For controlling the operation of the motor 1 a suitablethermostatic switch 15 is arranged in any convenient location in therefrigerator. This switch is so designed as to operate the motor whenthe temperature in there r er ator risesto a pre'deteined value c tostop the motor when the temperature is lowered to any predeterned value.

The calcium chloride or other equivalent substance is referahly arrangedon the outer surfaces of t e coils ofthe conder aud it may be retainedintheal contact na -m with by various expedients. In the preferredembodiment of the invention the calcium chloride is applied to the coilsin the form of a paint, thus forming an adherent layer 16 surroundingthe coils 17 With this arrangement the surface area 0f the condenser isnot diminished in size, but all of the heat transferred from therefrigerant to the surrounding air must pass through the walls of thecoils 17 and the layer of calcium chloride. Due-to the hygroscopic ordeliquescent propertiesof the layer or coating 16 the coils 17 are ineffect provided with a surrounding reservoir for a cooling fluid, whichreservoir is automatically replenishedby the chemical action of thematerial in absorbing moisturefrom the atmosphere.

In Figure 3 a considerably modified form of my invention is illustrated,for in this arrangement instead of employing calcium chloride as a solidsubstance surrounding the coils, it is dissolved in water forming asolutionin which the lowermost coils of the condenser are immersed.Thus, as shown, there is provided a suitable container 18 filled with acalcium chloride solution to immerse a certain portion of the condensercoils. In this construction the cooling is dueto the combined effects ofthe air circulating over the exposed'condenser coils and the evaporationfrom the solution in contact with the remaining coils during the runningperiods of the machine. 9 What I claim as my invention is:

1. The method of operating a coolingsysterm which consists inintermittently passing a heatedmedium through a cooling conduitsubstance in thermal contact with said conduit.

-3. The combination with a refrigerating system havinga compressor,condenser, expansion coils and meansifor intermittently circulating therefrigerating medium, of a deliquescent substance associated with saidcondenser for assisting in the condensation of therefrigerating medium.

4.- A condenser comprising a conduit for the medium to be'cooled andsolid calcium chloride arranged in thermal contact with said conduit. v

In testimony whereof I aflix my signature.

HAROLD A; GREENWALD.

